Year 2017 PPP (% of population) 1996 52 1997 73.9 1998 74.1 1999 79.6 2000 81.6 2001 83.5 2002 72.7 2003 72 2004 70 2005 71.7 2006 72.7 2007 74.1 2008 70.2 2009 70.5 2010 70.6 2011 69 2012 65.5 2013 60 2014 57 2015 56.2 2016 56.3 2017 53.9 2018 53.9 2019 54.2 2020 58.3 2021 55.4